The Irish film-maker John Carney has issued an apology, days after publicly criticising Keira Knightley during an interview with the Independent. Carney worked with the actor on his hit 2013 romantic comedy, Begin Again, and had described her in the interview as a “supermodel”, adding that she hadn’t got the essence of her character, a singer-songwriter, and was constantly surrounded by an entourage.

On Twitter, Carney posted a screenshot of a typed statement saying: “I’m ashamed of myself that I could say such things and I’ve been trying to account for what they say about me. In trying to pick holes in my work, I ended up blaming someone else.”

“Keira was nothing but professional and dedicated during that film and she contributed hugely to its success,” he added, before concluding that what he said about the actor is “not something I could ever justify, and will never repeat”.

In the interview – done to promote the release of his latest film, Sing Street – Carney had said that Begin Again had taught him “never [to] make a film with supermodels again.”

“Keira’s thing is to hide who you are, and I don’t think you can be an actor and do that,” he had said of his experience working with her. “I don’t want to rubbish Keira, but you know it’s hard being a film actor, and it requires a certain level of honesty and self-analysis that I don’t think she’s ready for yet and I certainly don’t think she was ready for on that film.”

Following the comments, many directors who had worked with Knightley rallied to her defence.